Barry and Iris are attending the activation of the particle accelerator when someone steals Iris's bag in episode #101. Hartley Rathaway shows Cisco some evidence of the fate of Ronnie in episode #112 "Crazy for You". The Flash team watches Ray Palmer's arrival here with Felicity in episode #118 "All Star Team Up".
Etta and Simon talk about the discovery of Walter's body in episode #419 "Letters of Transit". Filmed in the CBC Breezeway.
From episode #418 "The Consultant".